MY PARENT'S VEHICLE, A 2004 BUICK CENTURY, COLLIDED WITH A GUARD RAIL ON AN ENTRANCE RAMP TO I-81 IN CHRISTIANSBURG, VA. THEY WERE WEARING SEAT BELTS/SHOULDER HARNESS. MAIN IMPACT WAS FRONT LEFT BUMPER, WHICH WAS PUSHED IN ~ 3 FEET IN A NARROW INDENTATION; HOOD WAS CRUMPLED. THERE WAS DAMAGE TO LEFT SIDE OF VEHICLE. THE AIR BAGS DID NOT DEPLOY. BOTH PASSENGERS SUSTAINED INJURIES AND WERE TAKEN TO LOCAL HOSPITAL'S EMERGENCY ROOM. I SUSPECT THEIR INJURIES WOULD HAVE BEEN LESS SEVER HAD THE AIR BAGS DEPLOYED. DAMAGE TO VEHICLE IS VERY EXTENSIVE. *NM UPDATED 12/05/06. *JB